SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f6563f107120fb19cf6512dc87813e928d6a9c74c197acbeb4452727fc0fe88f' 
  AND token = 'e//w6vHqGkwIcF/9qHTX3RpdFhdj+qy7Hgda6/ZiDWQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}